Method of making a valve



Patented Sep t.' 15 1931' s UNITED STA TES PATENT OFFICE' ROBERT JARDINE, OF IDE'I'BOIT, 'EICHIG AN ASSIGNOR TO BICH TOOL COMPANY, OF

DETROIT, MICEIGAN, A `COBPOBATION OF MAINE :amon on uxme A VALVE Application filed March 18, 1927. Serial No. 176,*148.

This invention relates to valves and articularly to the poppet type of valve w ich is used in internal combustion engines.

One object of the invention is th'e provision 5 ofa method of manufactu're by which a hollow valve of this type containng a quantity of cooling medium may be cheaply and conveniently constructed. i j

Another object of the invention is .the proo vision of a method of manufacturing'engne poppet-valves which contain a quantity of cooling medium, so that the valve. may be permanently closed to obtain a pressuretight' seal and insure the retention of the 16 cooling medium within the valve.

A further object of the invention is the provision of a hollow valve having a portion swaged together and closed in such a manner as to permanently and perfectly seal the cool- 2 ing medium in the valve.

Further ob'ects and advantages ofthe in- Vention will be more fully set forth n the following .description and in the accompany-` ing drawings in which Figs. 1 to 4 show the successive steps taken in the manufacture of a valve, Fig. 1 showingin section the first step of the process, Fig. 2 showing the stem end of the valve swaged together, Fig. 3 showing the stem end after the' machining operation has taken place, and Fig. 4 showing the completed valve in section. C

' Fig. 5 is a central setctionthrough a modified form of -construction. i

In the manufacturing of poppet valves used in internalcombustion engines it has been i proposed to construct the-valve so that -it is provided with a hollow interior which is partheat`from the head end of the valve maybe conducted in an eflicient manner to the stem Where' it may be more readily dissipated. By the use ofsuch a Construction the excessive heat attained at the head end of the valve, especi'ally where the valve is used to regulate the cxhaust of the engine, may be quickly conducted away from the hot end so that the valve may operate at a comparatively cool temperature. It has been proposed to partly 'valve so that the high temperatures and the ly filled with a cooling medium, so that the fill the stem of the valve with a. mixture of salts of potassium nitrate and sodium nitrate, and one composition of a cooling medium is 55% potassium nitrate and sodium nitrate. Such a mixture of salts of the alkali metals has a melting temperature of about 425 degrees F. which is well below the working temperature of the portions of the valve With which the medium is in contact. The salt mixture just mentioned is intended to be, ao merely an example of a suitable cooling medium which may be provided within the valve. It has been found desirable to permanently seal the cooling medium within the hollow rapid motion'and impacts to which the valve is subjected will not cause the less of an of'the cooling medium. In accordance wit the invention whicli will now be described the end of the valve may be permanently and per; fectly sealed so as to efl'ectively retain the cooling medium in the valve.

Referrng now to the 'acc'ompanying drawings by reference numerals inwhich like numerals designate corresponding parts in various views, Fig. 1 shows a metal valve part which is' constructed as the first step of the process. This valve part designated generally 10 is comprised of a head 11 and the stem 12. This stem' is hollow, and within its entire length is an interior bore 13 which extends substantially up and into the head of the valve. Adjacent the open end of the stem the valve walls are enlarged and thickened at 14, the enlarged portion increasing gradually as shown at 15 and 16 from the thinner portions of the stem wall at each side of the enlargement. The interior bore 13 is-of a con- 'stant diameter from the open end 17 to the a small longitudinal central passage 25 being left after the swaging operation is competed.

Since the surfaces 15 and 16 interconnecting the enlargement 14 and the thinner portions of the stem of the valve adj'acent thereto are conically tapered in a gradual manner as shown,-the outside of the stem of the valve will be substantally of a uniform diameter after the swagingoperation 'just mentioned has been completedg, p

h After the stem end-of the valve has been substantially closed together by the swaging operation mentioned the end of the valve is machined so that a groove is provided to receive the customary collet or other spring retaining device. At the same time the outside diameter of the 'valve is machined to the proper size. The very restricted central longitudinal opening 25 is then enlarged by a drillingoperation so that a bore 31 of a definite desired size is provided in the end of the valve as shown in Fig. 3. The outer end of this end bore 31 is counter-bored at 32 to provide a tapering surface at this point. The end'surface 33 is machined so that the valve is of suitable length.

After the machining operation completes the form of the end of the valve stem the proper amount of cooling medium issupplied to the interior of the valve. In case a sodium nitrate and potassium nitrate miXture is to be used' as a cooling medium these substances are supplied in the form of a powder through' the opening 31 in the stem' end of the valve.

This opening 31 need only be of suificient size so that the salts or other cooling medium may be Conveniently supplied. After the metal salts or other cooling medium has been sup- 31 in the end of the valve.

plied to the interior of the valve in the proper amount so that the valve may be efliciently cooled, a metal plug 35 is forced into the hole After the plug 35 is in place the end portion '36 which has been I previously counter-sunk is filled in by welding, a good wearing material being utilized plug 35, which may if desired be slightly tapered to provide for its convenient inser- P tion', prevents the arc and the heat of the weld from coming into direct contact with the coolingsalts and permits the convenient handling of the valve during the welding operation.

By swaging the walls of the valve together as shown in Fig. 2 the weld which closes the endofthe valve may be made of a minimum size. It is desirable to have a minimum amount of material added by the weld so that the possibility of an unsecure weld ,or of a leaky connection at the weld will be minimized. However, it is undesirableto completely swage the open stem end of the valve in the head end of the valve.

together as the central passage 25 may only 'of course, the head end of the valve is kept down 's`o that theloss of the material is prevented( Fhe heating of the valve has the eifect of liquefying the cooling material, and when the valve is subsequently cooled this cooling material is retained in a solid state The open stem end of the valve may then be swaged together as previously described and the stem end-may be machined as shown in Fig. 3 to receive the plug 35 and permit the later welding of the a center of the end surface of the valve. It is unneeessary, however, to re-bore the 'central passage after the swaging operation has been completed if the cooling medium has already been placed in the valve. The swaging of thestem end of the valve may be completed in such a manner that the central passage through the end of the valve is substantially closed. To nsure the complete and permanent scaling of this central passage the end of the valve at the very center portion may be spot-welded as by the use of an acetylene torch.

As shown in Fig. 5 the stem end of the valve has been practically completely swaged together along the line 40.. In the Construction of a valve as shown in Fig. 5 the cooling medium as indicated at 41 and whichmay consist of the mixture of potassium and sodium salts previously mentioned is supplied to' the interier of the valve beforethe swaging operation isvstarted. -The metal valve part as shown in Fig. 1 istherefore filled with A the desired amount of cooling medium 41 and subsequent solidifying of the cooling medium in the head end of the valve.

ortion 42 is then swaged together during which the solidified cooling material is retained in the head endof the valve. The collet receiving groove` 43 may then be machined in the stem end of the valve and this The stern stem cut off to the desired length by machining the end surface'44. This surface is preferably made perfectly flat and to it is welded a flat valve tip 45 so that the butt-weld by which the fastening of the tip 45 is eflz'ected is of a; maximum area. i T'he area of contact of the weld' or joint at the valve tip is substantially the same' as the entire cross-sectional area of the valve since. the restriction' at 40 is of a negligible size. The weld is thus exceedingly strong and serves to efi'ectively and permanently seal the small open end of the' restriction 40 and to firmly attach the tip in place. The tip 45 is preferably constructed of a material which may receive the impact and pounding of the cam by which y the valve is operated. The main portion of the valve may be made of iron or steel of a suitable composition so that the swaging operation may be Conveniently etfected and so that the head end of the valve may resist the heat to which it must be subjected. The tip 45 has been shown of comparatively small length but it is unnecessary to cause the joint between the tip and the swaged end of the valve to be between the valve end and the collet 43. This depends upon the particular circumstances and upon the difierent materia'ls from which the tip and the main valve operation are constructed.

While the methods herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these' precise methods, and that changes may be made in them without departing from the scope of the invention which is defined in the appended claims.

What isclaimed is 1. The method of making a valve 'for internal combustion engines comprising making a metal valve part embodying a valve head and a valve stem formed integrally therewith 'and having an enlargement adjacent the stem end, machining a hole in the stem from the stem end, and swaging the stem end together.

2. The method of making a valve for internal combustion engines comprising making a metal valve part embodying a valve head and a valve stem of one piece Construction and having an enlargement adjacent the stem end, drilling a hole in the stem from the stem end thereoit', drawing the stem end concentrically together to restrict the opening, and perman'ently sealing the restricted opening.

3. The method of making a valve for internal combustion engines comprising making a metal valve part having a hollow stem open at the stem end and having an enlargement adj acent the stem end, drawing the said end concentrically together, partly filling the hollow stem with cooling material, and then permanently and entirely closing the drawn end.

4. The method of making a valve comprising making a metal valve part having a hollow stern open at the stem end, swaging the stem send concentrically together to restrict the opening at the stem end, partly filling the hollow stem with cooling material, machining the end of the valve stem, and then closing the restricted opening so as to permanently seal the cooling material in a pressure tight manner.

5. The method of making a valve comprising making a metal valve part having a hollow stem open at the stem end, drawing the stem end together concentrically, enlarging the central passage through the stem end, inserting a precletermined amount of cooling material through the enlarged passage, and then welding the end of the enlarged central passage to permanently seal the cooling material within the valve in a pressure tight manner.

6. The method of making a valve comprising making a metal valve part having a hollow stem open at one end, drawing the open end of the valve so as to concentrically reduce the opening through the same, inserting a predetermined amount of cooling material within the hollow valve stem, heating the valve to cause the cooling material to be rei through the open end of the stem, heating the valve to liquefy the material within the valve, pcrmitting the valve 'to cool to cause the solidification of the cooling material in the head end of the valve and then reducing the opening in the open end of the valve by drawing the said end together concentrically.

8. The method of making a valve comprising making ametal valvepart having a hollow stem open at the stem end, insertin g a predetermined amount of cooling material through the open end of the stem, heating the valve to liquefy the material within the valve, and permitting the valve to cool to cause the solidification of the cooling material in the head end of the valve, reducing the opening in the open end of the valve by drawing the said end together concentrically, and permanently closing the reduced passage through the end of the stem and machining the stem end of the valve.

` 9. The method of making an engine valve comprising making an integrally headed valve part, drilling the valve part from the stem end, partly closing in the end of the stem except for a small central opening much smaller than the internal diameter of the drilled hole, inserting a predetermined amount of cooling material through the central opening, welding the end of the stem to permanentl'y seal up the small central opening and permanently seal the cooling material nature.

ROBERT J ARDINE. 

